Skip to content

XTX301 in Patients With Advanced Solid Tumors

A First-in-Human, Multicenter, Phase 1/2, Open-Label Study of XTX301 in Patients With Advanced Solid Tumors

Status
Recruiting
Phases
Phase 1Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05684965
Enrollment
358
Registered
2023-01-13
Start date
2023-05-11
Completion date
2028-09-01
Last updated
2026-06-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Advanced Solid Tumor

Brief summary

This is a first-in-human, multicenter, Phase 1/2, open-label study designed to evaluate the safety and tolerability of XTX301 as monotherapy in patients with advanced solid tumors.

Detailed description

This is a first-in-human, multicenter, Phase 1/2, open-label study designed to evaluate the safety, tolerability, PK, PD, immunogenicity, and antitumor activity/efficacy of XTX301, a tumor-activated interleukin-12, as monotherapy in patients with advanced solid tumors. Phase 1. Part 1A will examine XTX301 monotherapy in a standard 3+3 dose escalation design. Based on the results of Part 1A, patients with select advanced solid tumors will be enrolled in Part 1B, which will evaluate XTX301 monotherapy in relation to specific PD biomarkers. Phase 2 will further evaluate the safety and antitumor activity/efficacy of XTX301 monotherapy in disease-specific expansion cohorts of patients with select tumors, namely: head and neck squamous cell carcinoma (HNSCC), melanoma (patients with uveal melanoma are excluded), non-small cell lung cancer (NSCLC), ovarian cancer, castrate-resistant prostate cancer (CRPC)/androgen pathway modulation-resistant prostate cancer (APMR-PC), triple-negative breast cancer (TNBC)

Interventions

DRUGXTX301

XTX301 monotherapy

Sponsors

Xilio Development, Inc.
Lead SponsorINDUSTRY

Study design

Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

• Disease Criteria: Part 1A - Any histologically or cytologically confirmed solid tumor malignancy that is locally advanced or metastatic and has failed standard therapy, standard therapy does not confer survival benefit, or standard therapy is not available. Part 1B- Any histologically or cytologically confirmed solid tumor malignancy among the tumor types outlined below, that is locally advanced or metastatic and has failed standard therapy, standard therapy does not confer survival benefit, or standard therapy is not available. Patients with the following tumor types are eligible for Part 1B: melanoma, NSCLC, HNSCC, TNBC, cervical cancer, microsatellite instability high/mismatch repair deficient (MSI-H/dMMR) colorectal cancer, or MSI-H/dMMR endometrial cancer. Note: Based on evolving internal and external data, the Sponsor may decide to open a "backfill cohort" in Part 1B for patients with any of the following solid tumors: prostate cancer, ovarian cancer, pancreatic cancer, microsatellite stable colorectal cancer, T-cell lymphoma. Phase 2 - All patients must have measurable disease at baseline per RECIST 1.1, except patients with CPRC/APMR-PC. Additional disease-specific criteria per cohort are as follows: i. Cohort 2A: head and neck squamous cell carcinoma (HNSCC). Must have histologically or cytologically confirmed locally recurrent or metastatic HNSCC previously treated with 1 to 2 lines of therapy (therapy given in the curative setting or radiotherapy alone would not be counted as a line of therapy). Unless contraindicated, prior therapy must have included PD-1/PD-L1 inhibitor and/or platinum-based chemotherapy per local and institutional standard of care. Patients who received prior PD-1/PD-L1 inhibitor must have derived clinical benefit, i.e. either achieved a partial response (PR) or CR or have remained stable on PD-1/PD-L1 therapy (alone or in combination) without progression for at least 6 months. Patients must have a known human papillomavirus (HPV) status (either HPV-positive or HPV-negative). Patients with known or suspected invasion or encasement of major vessel or with active or imminent airway obstruction are excluded. ii. Cohort 2B: melanoma. Must have unresectable or metastatic melanoma previously treated with 1 to 2 lines of therapy in the recurrent or metastatic setting. Unless contraindicated, prior therapy must have included a PD-1/PD-L1 inhibitor alone or in combination. Patients with known BRAF V600-activating mutation must have previously received targeted therapy per local and institutional standard of care. Note: patients with uveal melanoma are excluded. iii. Cohort 2C: non-small cell lung cancer (NSCLC). Must have histologically confirmed locally advanced or metastatic NSCLC previously treated with 1 to 2 lines of therapy. Unless contraindicated, prior therapy must have included a PD1/PD-L1 inhibitor and a platinum-based regimen, given either concurrently or separately per local and institutional standard of care. Patients with known genomic alteration for which a targeted therapy is approved (e.g. ROS1 fusion, NTRK fusion, BRAF V600E mutation, EGFR mutation, or ALK fusion) must have been previously treated with relevant targeted therapy per local and institutional standard of care. iv. Cohort 2D: ovarian cancer. Must have histologically confirmed epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer with current platinum-resistant disease per investigator's assessment (e.g. patient is not eligible for further platinum-containing treatment). Patients must have previously experienced a response lasting at least 180 days to first-line platinum-based therapy. Patients who have been unable to tolerate platinum therapy are also eligible. Unless contraindicated, patients with known BRCA mutation must have received a poly(ADP-ribose) polymerase (PARP) inhibitor. v. Cohort 2E: castrate-resistant prostate cancer (CRPC)/androgen pathway modulation-resistant prostate cancer (APMR-PC). Histopathologically or cytopathologically confirmed adenocarcinoma without neuroendocrine differentiation or small cell features. Must have metastatic disease either on bone scan and/or in soft tissue by CT or MRI. Patients without measurable extra-skeletal lesions must have prostate-specific antigen (PSA) levels ≥ 2 ng/mL at screening. Must have been previously treated with an androgen receptor pathway inhibitor (e.g. abiraterone, enzalutamide, darolutamide, or apalutamide) and/or chemotherapy per local and institutional standard of care. Baseline total testosterone must be ≤ 50 ng/dL (≤ 2.0 nM), and surgical or ongoing medical castration must be maintained throughout the duration of the study. Patients receiving anti-resorptive agent (e.g. bisphosphonate, denosumab) therapy must have been on stable regimen prior to study entry. vi. Cohort 2F: triple-negative breast cancer (TNBC). Must have metastatic TNBC with disease relapse after 2 to 4 previous lines of therapy per local and institutional standard of care. Neoadjuvant and/or adjuvant chemotherapy will count as 1 prior line of therapy only if recurrence during or within 6 months of completing adjuvant systemic therapy. Unless contraindicated, patients with known actionable mutations (e.g. BRCA1 or BRCA2) must have received prior therapy with the corresponding targeted agent per local and institutional standard of care * ECOG performance status of 0-2 for Phase 1 * ECOG performance status of 0 or 1 for Phase 2 * Adequate organ function * Tumor tissue samples: Part 1B: patients must have lesions amenable to biopsy and be willing and able to provide fresh tumor biopsies before and after initiation of treatment * Patients with recent major surgery must have adequately recovered with no ongoing complications from the surgery before receiving study drug

Exclusion criteria

* Prior treatment with IL-12 therapy (any form, e.g. recombinant human, prodrug, intratumoral, etc.) * Known liver metastasis based on imaging * Possible area of ongoing necrosis (non-disease-related), such as active ulcer, nonhealing wound, or intercurrent bone fracture * Active primary central nervous system (CNS) malignancy, CNS metastases, and/or carcinomatous meningitis * Active autoimmune disease * History of Grade ≥ 3 immune-related adverse events associated with prior immunotherapy unless these were adequately resolved with therapy within 14 days * A diagnosis of immunodeficiency; receiving chronic systemic therapy exceeding prednisone 10 mg daily or equivalent or any other form of immunosuppressive therapy within 7 days before the first dose of study drug * Active hepatitis B or active hepatitis C infection * Prior treatment with gene therapy, organ transplant, or hematopoietic stem-cell transplant * Known malignancy (other than disease under study) that is progressing or has required active treatment within the past 3 years

Design outcomes

Primary

MeasureTime frame
Incidence of Dose Limiting Toxicities (DLTs) (Part 1A only)From the first dose of the study drug at Cycle 1 Day 1 up to next applicable cycle visit (Cycle 2 Day 1 or Cycle 3 Day 1). Approximately 21 to 42 days. Each cycle is 21 days.
Incidence of treatment-emergent adverse events (TEAEs) and changes in clinical laboratory valuesUp to 24 months
Investigator-assessed objective response rate (ORR) per RECIST 1.1 (for all Phase 2 disease specific cohorts except CRPC/APMR-PC)up to 24 months
PSA50 response rate and Investigator-assessed ORR per RECIST 1.1 by CT/MRI for patients with measurable disease (for Phase 2 CRPC/APMR-PC cohort only)up to 24 months

Secondary

MeasureTime frame
Plasma concentrations of XTX301Up to 24 months
Maximum observed plasma concentration (Cmax)Up to 24 months
Time of maximum observed concentration (Tmax)Up to 24 months
Trough concentration (Ctrough)Up to 24 months
Area under the curve (AUC)Up to 24 months
Half-life (T1/2)Up to 24 months
Systemic clearance (CL)Up to 24 months
Volume of distribution (Vd)Up to 24 months
Antidrug antibody (ADA) occurrence and titer in serumUp to 24 months
Investigator-assessed objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 (Phase 1 only)Up to 24 months
Duration of response (DOR) (Phase 2 only)up to 24 months
Disease control rate (Phase 2 only)up to 24 months
Progression-free survival (PFS) (Phase 2 only)up to 24 months
Overall survival (OS) (Phase 2 only)up to 24 months
For CPRC/APMR-PC (Cohort 2E), Investigator-assessed response rate based on PCWG3 criteria (Phase 2 only)up to 24 months

Countries

United States

Contacts

CONTACTXilio Medical Affairs
medicalaffairs@xiliotx.com(857) 524-2466

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 24, 2026